Foldable Mud Flaps

I see a large number of piggy backs every week coming up to dealers in winnipeg from the states. Everyone has the same thing. 2x4 clamped onto the back frame with a set of mud flaps attached. Cheap, easy and legal.

 

Couldn’t you bolt them to a piece of angle iron, and vice grip them to the frame?

 

If I understand the problem, it’s the long 2x4 that’s bulky. I suggest cheap flap brackets that go into bracket. You might find enough holes in the frame, to bolt it direct, or get a bracket welded up that you can clamp to the frame. Here are pics of the bracket and the hanger. No more long 2x4’s.
Back in the day, we used burlap grain sacks, nailed to a 2x4, with furring strips on the bottom of the sacks to weigh it down. Of course they hadn’t even invented the DOT yet!

 

I suggest:
2 cheap Betts straight hangers
2 cheap flexible flaps
2 Betts brackets
1 length capped light 1 1/2 angle iron 1" longer than frame width
2 c clamps

bolt the brackets to the end caps
clamp the unit to the frame
pin the flaps(mounted on hangers) on

at the other end roll each flap around the bracket and carry all three pieces and
the clamps as a package.